SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '337cc2a6f5b04b70055bc4679227cba397b119cfd278d325dc765f15ef54d67b' 
  AND token = 'O/3GzrPxZ+YOey/xzE2DN2VKTBl0R94k8Y3ZuLirBWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}